Volcanic activity at Erta Ale discussed in the 5-11 October 2005 Weekly Volcanic Activity Report actually occurred at Dabbahu. The correct report is below.
A team of scientists visited the Da'Ure locality immediately adjacent to the NE flank of the Quaternary Dabbahu (or Boina) felsic complex on 4 and 5 October after receiving reports of volcanic activity there on 26 September. People in the area noted that on 26 September at about 1300 a very strong earthquake shook the area, and was followed by a dark column of "smoke" that rose high into the atmosphere and spread out to form a cloud, which darkened the area for 3 days and 3 nights. The scientists determined that a minor explosive eruption occurred from two semi-circular vents, producing ashfall that was ~5 cm thick near the vent. Ash deposits extended more than 500 m from the vent. Boulders emitted during the eruption were as large as 3 m and were deposited as far as 20 meters away. The scientists noted intense degassing from the vents, the scent of sulfur dioxide, and the sound of boiling water in the vents. As of about 10 October, the Addis Ababa University Geophysical Observatory reported that seismic activity in the area was continuing.
Source: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University
First historical eruption on 26 September; ash emission and a pumice dome
An eruption began on 26 September 2005 in the Afar triangle region of NW Ethiopia, near the Afar's W topographic margin, a spot ~ 330 km E of Lake Tan'a (the source of the Blue Nile river) and ~ 320 km NNW of the city of Djibouti. The venting took place on the flanks of Dabbahu (Boina), a volcano without previous historical eruptions. What follows is a brief synopsis of seismicity available from the USGS and some field observations from Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele of Addis Ababa University (AAU). Shortly after the Bulletin editors received the AAU report, normal lines of communication were temporarily halted due to civil unrest. Consequently, this report was reviewed and augmented by Anthony Philpotts of the University of Connecticut, who had flown to Erta Ale and Dabbahu with them and other scientists on 16 October 2005.
Dabbahu, a stratovolcano, also goes by several other names, including Mount Dabbahu, Boina, Moina, and Boyna. The eruption occurred at least 5 km NE of Dabbahu's summit area, at a flat spot referred to by the names Da'Ure and Teru Boyna. The profusion of names and spellings for this region of Africa partly stems from widely dissimilar alphabets; the one used in the region has over 100 letters, complicating conversion into languages having only 26.
The Dabbahu eruption has been confusing. Initial news reports shed little light on the eruption's source, size, or impact. Several news reports stated that nearby earthquakes had caused an eruption at Erta Ale, which is 113 km N of Dabbahu, but that was not the critical eruption in this region during late September. (Seismicity, however, did appear associated with an elevated level of unrest at Erta Ale in October-see report in this issue.) The confusion propagated into the Smithsonian-USGS Weekly Report of 5-11 October 2005, which incorrectly attributed some details of the Dabbahu eruption to Erta Ale. A correction was issued and the report was withdrawn. Official sources and news reports also seem to have initially overstated the impact (e.g., statements like 50,000 nomads evacuated, almost 500 goats killed, etc.).
In a later, more measured report, The Ethiopian Herald posted a 6 October article on the web that noted the following.
"... the [Disaster Prevention and Preparedness Commission] has sent relief aid, household utensils and a tanker truck to areas affected by the natural disaster. A regional committee set up in charge of studying the magnitude of the disaster has already sent its report to the commission. According to the report, 1,215 quintals [121,500 kg] of food aid has been dispatched to 6,384 citizens displaced from Boya and Debawo ... and resettled in Debabo locality, 20 km from Teru. Some 18,234 various household utensils, 1,280 blankets as well as 119 roles of plastic sheets were being transported to the area."
According to faculty at Addis Ababa University, prior to the eruption and in addition to the earthquake swarm there was also volcanic tremor, as well as faulting, fracturing, and possible local landslides.
Earthquake swarm. During September-4 October 2005, an earthquake swarm consisting of 131 events occurred at and immediately surrounding Dabbahu (figure 1 and table 1). The swarm was sudden and comparatively intense, with magnitudes ranging from body-wave magnitude (mb) 3.9 to 5.2. Instruments registered earthquakes of both the highest number and magnitude during 24-26 September, just prior to the 26 September eruption. Seismicity in the area declined sharply on 27 September and stopped on 4 October. According to another data set, earthquakes occurred in the region during the 5 years prior to this swarm at an average rate of ~ 12 per year.
Date | Events | Maximum Magnitude |
14 Sep 2005 | 1 | 4.6 mb |
20 Sep 2005 | 2 | 5.5 Mw |
21 Sep 2005 | 16 | 4.9 mb |
22 Sep 2005 | 12 | 4.9 mb |
23 Sep 2005 | 9 | 4.8 mb |
24 Sep 2005 | 29 | 5.6 Mw |
25 Sep 2005 | 42 | 5.2 mb |
26 Sep 2005 | 9 | 5.2 mb |
27 Sep 2005 | 1 | 4.5 mb |
28 Sep 2005 | 5 | 5.1 mb |
29 Sep 2005 | 2 | 4.8 mb |
01 Oct 2005 | 1 | 4.5 mb |
02 Oct 2005 | 1 | 5.0 mb |
04 Oct 2005 | 1 | 4.5 mb |
First-hand observations. Gezahegn Yirgu of AAU submitted a preliminary description of the eruption. He reported that people in the area noted that on 26 September at about 1300 a very strong earthquake occurred. That was followed by a dark column of "smoke" that rose high into the atmosphere and spread out to form an umbrella-shaped cloud. Emissions darkened the area for 3 days and 3 nights. On their first visit, provoked by the abnormal seismicity, his team departed the site just two hours before the 26 September eruption. He went back to Dabbahu for several more visits, some of which included geologists from overseas.
The visitors found that a minor explosive eruption had taken place from a fissure-vent system, producing a light-colored ash layer that extended over 500 m from the vent (figure 2). The eruption threw out pre-existing near-surface pyroclastic deposits (sediments) and felsic lavas, and redeposited them near the vent (figure 3). Some of the rocks that were thrown 20 m from the vent measured 2-3 m across. Fine white ash fell in the surrounding region as far as Teru village, 40 km SW of the eruption site.
Roughly two-thirds of the way from the S end of the fissure vent, a 30-m-diameter pumice dome formed. From within the fractures in this dome, the team heard a sound from below resembling the sound of a helicopter engine or a boiling liquid.
The bulk of Yirgu's report on the second visit to the eruption site, on 4-5 October, follows.
"A team of three geologists and one geophysicist (Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele) revisited the Da'Ure locality (at approximately 120° 43' 37" N, 40° 32' 55" E) immediately adjacent to the NE flank of the Quaternary Boina felsic complex. This locality is the southwestern extension of the area we visited a week earlier and where we observed a number of newly opened parallel fissures and a major reactivated normal fault.
"We first investigated the area where a volcanic eruption had been reported. Here we observed the presence of a wide and elongate fissure more than 500 m long and about 60 m deep [(figures 2-4)]. The elongate fissure attains a maximum width of about 100 m where a semi-circular pit has formed and from where the explosive eruption appears to have taken place. This elongate vent is oriented almost N-S [trending N10W] and has broken through felsic pyroclastic deposits and lavas. Two smaller pits were also observed farther N along the fissure [situated] to the N of the major pit. A very fine and light grey ash has been deposited on both sides of the elongate fissure with the ash cover extending more than 500 m away from the vent. Beneath the ash deposit lies a sequence of loose layers consisting of mixed volcanic ash and ejecta from pre-existing fissure wall rocks. These layers have a total thickness of about 20 m near the large pit."
At the pumice dome Yirgu noted "... intense degassing is occurring with the production of SO2 as evidenced by its smell as far as 500 m away. Degassing is also visible along the length of the vent as well as through nearby fissures. The local people have reported that on 26 September 2005 at about 1300 local time a very strong earthquake shook the area. This was followed by a dark column of 'smoke' that rose high into the atmosphere and spread out to form a cloud, which darkened the area for three days and three nights. Our field observations were consistent with . . . [a minor ejection] of volcanic ash from a small vent or vents along the opened fissure."
"In the same locality, we also studied the newly formed second-order fractures and fissures, most of which were located on the eastern side of the main eruptive fissure/vent. Here, the [roughly N- to S-trending] fractures and fissures were all parallel to each other .... They were better developed on unconsolidated pyroclastic deposits and sediments; they affected an area nearly 700 m away from the main eruptive vent/fissure; spacing is commonly between 10 and 20 m; some extend discontinuously along strike for over 500 m, as observed from the helicopter; open fissures in the pyroclastic deposits measure up to 20 cm wide with common elliptical pits or collapse structures between fissures up to 4 m wide and up to 4 m deep.
"We have also observed a major reactivation on a N- to S-trending normal fault located some 500 m to the E of the elongate eruptive vent/opening. This fault breaks through felsic lavas and unwelded pyroclastic deposits and has a reactivated displacement (down thrown to the W) reaching half a meter in places. This reactivated fault extends . . . discontinuously for at least three kilometers as observed from the helicopter. Degassing is occurring along some parts of this fault."
Yirgu also said that, according to the AAU Geophysical Observatory, seismicity continued in early October in the area affected by the eruption, faulting, and fissuring.
Other data from a 16 October visit. Anthony Philpotts accompanied a team who, along with AAU colleagues, were helicoptered to the eruption site, which had completely ceased by this time. At the eruption site and on the helicopter trip to and from it, he saw no dead nor injured livestock. The team also visited a refugee camp for displaced nomads.
In discussions with AAU colleagues who saw the fissure vent during multiple visits, and in comparing photographs, it appeared that material exposed at depth in the wall of the vent changed to a lighter color. Presumably, these color changes were linked to water, initially present but that had evaporated in the intense heat of the Afar day. Philpotts suggested that if the vent did provide a window into the water table, groundwater may have added to the explosive activity.
Philpotts said that when they arrived, on 16 October, the pumice dome (shown in close-up in figure 5) still yielded temperatures of 400°C in cracks. The pumice dome lacked any deposits on top of its upper surfaces, and thus clearly represented the last volcanic feature to form. Some post-eruptive faulting was noticed with offsets on the order of 10 m.
Philpotts made several thin sections of pumice dome samples, and found it to be almost totally aphyric. It contains a very few rounded (resorbed) sanidine phenocrysts (figure 6) and needle-shaped microlites with high refractive index (pyroxene?). He noted that "The microlites undoubtedly formed during emplacement of the dome, but the resorption of the sanidine phenocrysts must have occurred at depth prior to eruption and probably indicates heating of the source magma chamber with an influx of hotter (basaltic?) magma."
Information Contacts: Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele, Department of Earth Sciences, Addis Ababa University, PO Box: 1176, Addis Ababa, Ethiopia; Anthony Philpotts, University of Connecticut, U-45, Beach Hall, Storres, CT 06269, USA; National Earthquake Information Center (NEIC), US Geological Survey, Geologic Hazards Team Office, Colorado School of Mines, 1711 Illinois St., Golden, CO 80401, USA (URL: https://earthquake.usgs.gov/); The Ethiopian Herald, Addis Ababa, Ethiopia.
2005: October
Volcanic activity at Erta Ale discussed in the 5-11 October 2005 Weekly Volcanic Activity Report actually occurred at Dabbahu. The correct report is below.
A team of scientists visited the Da'Ure locality immediately adjacent to the NE flank of the Quaternary Dabbahu (or Boina) felsic complex on 4 and 5 October after receiving reports of volcanic activity there on 26 September. People in the area noted that on 26 September at about 1300 a very strong earthquake shook the area, and was followed by a dark column of "smoke" that rose high into the atmosphere and spread out to form a cloud, which darkened the area for 3 days and 3 nights. The scientists determined that a minor explosive eruption occurred from two semi-circular vents, producing ashfall that was ~5 cm thick near the vent. Ash deposits extended more than 500 m from the vent. Boulders emitted during the eruption were as large as 3 m and were deposited as far as 20 meters away. The scientists noted intense degassing from the vents, the scent of sulfur dioxide, and the sound of boiling water in the vents. As of about 10 October, the Addis Ababa University Geophysical Observatory reported that seismic activity in the area was continuing.
Source: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University
Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.
First historical eruption on 26 September; ash emission and a pumice dome
An eruption began on 26 September 2005 in the Afar triangle region of NW Ethiopia, near the Afar's W topographic margin, a spot ~ 330 km E of Lake Tan'a (the source of the Blue Nile river) and ~ 320 km NNW of the city of Djibouti. The venting took place on the flanks of Dabbahu (Boina), a volcano without previous historical eruptions. What follows is a brief synopsis of seismicity available from the USGS and some field observations from Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele of Addis Ababa University (AAU). Shortly after the Bulletin editors received the AAU report, normal lines of communication were temporarily halted due to civil unrest. Consequently, this report was reviewed and augmented by Anthony Philpotts of the University of Connecticut, who had flown to Erta Ale and Dabbahu with them and other scientists on 16 October 2005.
Dabbahu, a stratovolcano, also goes by several other names, including Mount Dabbahu, Boina, Moina, and Boyna. The eruption occurred at least 5 km NE of Dabbahu's summit area, at a flat spot referred to by the names Da'Ure and Teru Boyna. The profusion of names and spellings for this region of Africa partly stems from widely dissimilar alphabets; the one used in the region has over 100 letters, complicating conversion into languages having only 26.
The Dabbahu eruption has been confusing. Initial news reports shed little light on the eruption's source, size, or impact. Several news reports stated that nearby earthquakes had caused an eruption at Erta Ale, which is 113 km N of Dabbahu, but that was not the critical eruption in this region during late September. (Seismicity, however, did appear associated with an elevated level of unrest at Erta Ale in October-see report in this issue.) The confusion propagated into the Smithsonian-USGS Weekly Report of 5-11 October 2005, which incorrectly attributed some details of the Dabbahu eruption to Erta Ale. A correction was issued and the report was withdrawn. Official sources and news reports also seem to have initially overstated the impact (e.g., statements like 50,000 nomads evacuated, almost 500 goats killed, etc.).
In a later, more measured report, The Ethiopian Herald posted a 6 October article on the web that noted the following.
"... the [Disaster Prevention and Preparedness Commission] has sent relief aid, household utensils and a tanker truck to areas affected by the natural disaster. A regional committee set up in charge of studying the magnitude of the disaster has already sent its report to the commission. According to the report, 1,215 quintals [121,500 kg] of food aid has been dispatched to 6,384 citizens displaced from Boya and Debawo ... and resettled in Debabo locality, 20 km from Teru. Some 18,234 various household utensils, 1,280 blankets as well as 119 roles of plastic sheets were being transported to the area."
According to faculty at Addis Ababa University, prior to the eruption and in addition to the earthquake swarm there was also volcanic tremor, as well as faulting, fracturing, and possible local landslides.
Earthquake swarm. During September-4 October 2005, an earthquake swarm consisting of 131 events occurred at and immediately surrounding Dabbahu (figure 1 and table 1). The swarm was sudden and comparatively intense, with magnitudes ranging from body-wave magnitude (mb) 3.9 to 5.2. Instruments registered earthquakes of both the highest number and magnitude during 24-26 September, just prior to the 26 September eruption. Seismicity in the area declined sharply on 27 September and stopped on 4 October. According to another data set, earthquakes occurred in the region during the 5 years prior to this swarm at an average rate of ~ 12 per year.
Date | Events | Maximum Magnitude |
14 Sep 2005 | 1 | 4.6 mb |
20 Sep 2005 | 2 | 5.5 Mw |
21 Sep 2005 | 16 | 4.9 mb |
22 Sep 2005 | 12 | 4.9 mb |
23 Sep 2005 | 9 | 4.8 mb |
24 Sep 2005 | 29 | 5.6 Mw |
25 Sep 2005 | 42 | 5.2 mb |
26 Sep 2005 | 9 | 5.2 mb |
27 Sep 2005 | 1 | 4.5 mb |
28 Sep 2005 | 5 | 5.1 mb |
29 Sep 2005 | 2 | 4.8 mb |
01 Oct 2005 | 1 | 4.5 mb |
02 Oct 2005 | 1 | 5.0 mb |
04 Oct 2005 | 1 | 4.5 mb |
First-hand observations. Gezahegn Yirgu of AAU submitted a preliminary description of the eruption. He reported that people in the area noted that on 26 September at about 1300 a very strong earthquake occurred. That was followed by a dark column of "smoke" that rose high into the atmosphere and spread out to form an umbrella-shaped cloud. Emissions darkened the area for 3 days and 3 nights. On their first visit, provoked by the abnormal seismicity, his team departed the site just two hours before the 26 September eruption. He went back to Dabbahu for several more visits, some of which included geologists from overseas.
The visitors found that a minor explosive eruption had taken place from a fissure-vent system, producing a light-colored ash layer that extended over 500 m from the vent (figure 2). The eruption threw out pre-existing near-surface pyroclastic deposits (sediments) and felsic lavas, and redeposited them near the vent (figure 3). Some of the rocks that were thrown 20 m from the vent measured 2-3 m across. Fine white ash fell in the surrounding region as far as Teru village, 40 km SW of the eruption site.
Roughly two-thirds of the way from the S end of the fissure vent, a 30-m-diameter pumice dome formed. From within the fractures in this dome, the team heard a sound from below resembling the sound of a helicopter engine or a boiling liquid.
The bulk of Yirgu's report on the second visit to the eruption site, on 4-5 October, follows.
"A team of three geologists and one geophysicist (Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele) revisited the Da'Ure locality (at approximately 120° 43' 37" N, 40° 32' 55" E) immediately adjacent to the NE flank of the Quaternary Boina felsic complex. This locality is the southwestern extension of the area we visited a week earlier and where we observed a number of newly opened parallel fissures and a major reactivated normal fault.
"We first investigated the area where a volcanic eruption had been reported. Here we observed the presence of a wide and elongate fissure more than 500 m long and about 60 m deep [(figures 2-4)]. The elongate fissure attains a maximum width of about 100 m where a semi-circular pit has formed and from where the explosive eruption appears to have taken place. This elongate vent is oriented almost N-S [trending N10W] and has broken through felsic pyroclastic deposits and lavas. Two smaller pits were also observed farther N along the fissure [situated] to the N of the major pit. A very fine and light grey ash has been deposited on both sides of the elongate fissure with the ash cover extending more than 500 m away from the vent. Beneath the ash deposit lies a sequence of loose layers consisting of mixed volcanic ash and ejecta from pre-existing fissure wall rocks. These layers have a total thickness of about 20 m near the large pit."
At the pumice dome Yirgu noted "... intense degassing is occurring with the production of SO2 as evidenced by its smell as far as 500 m away. Degassing is also visible along the length of the vent as well as through nearby fissures. The local people have reported that on 26 September 2005 at about 1300 local time a very strong earthquake shook the area. This was followed by a dark column of 'smoke' that rose high into the atmosphere and spread out to form a cloud, which darkened the area for three days and three nights. Our field observations were consistent with . . . [a minor ejection] of volcanic ash from a small vent or vents along the opened fissure."
"In the same locality, we also studied the newly formed second-order fractures and fissures, most of which were located on the eastern side of the main eruptive fissure/vent. Here, the [roughly N- to S-trending] fractures and fissures were all parallel to each other .... They were better developed on unconsolidated pyroclastic deposits and sediments; they affected an area nearly 700 m away from the main eruptive vent/fissure; spacing is commonly between 10 and 20 m; some extend discontinuously along strike for over 500 m, as observed from the helicopter; open fissures in the pyroclastic deposits measure up to 20 cm wide with common elliptical pits or collapse structures between fissures up to 4 m wide and up to 4 m deep.
"We have also observed a major reactivation on a N- to S-trending normal fault located some 500 m to the E of the elongate eruptive vent/opening. This fault breaks through felsic lavas and unwelded pyroclastic deposits and has a reactivated displacement (down thrown to the W) reaching half a meter in places. This reactivated fault extends . . . discontinuously for at least three kilometers as observed from the helicopter. Degassing is occurring along some parts of this fault."
Yirgu also said that, according to the AAU Geophysical Observatory, seismicity continued in early October in the area affected by the eruption, faulting, and fissuring.
Other data from a 16 October visit. Anthony Philpotts accompanied a team who, along with AAU colleagues, were helicoptered to the eruption site, which had completely ceased by this time. At the eruption site and on the helicopter trip to and from it, he saw no dead nor injured livestock. The team also visited a refugee camp for displaced nomads.
In discussions with AAU colleagues who saw the fissure vent during multiple visits, and in comparing photographs, it appeared that material exposed at depth in the wall of the vent changed to a lighter color. Presumably, these color changes were linked to water, initially present but that had evaporated in the intense heat of the Afar day. Philpotts suggested that if the vent did provide a window into the water table, groundwater may have added to the explosive activity.
Philpotts said that when they arrived, on 16 October, the pumice dome (shown in close-up in figure 5) still yielded temperatures of 400°C in cracks. The pumice dome lacked any deposits on top of its upper surfaces, and thus clearly represented the last volcanic feature to form. Some post-eruptive faulting was noticed with offsets on the order of 10 m.
Philpotts made several thin sections of pumice dome samples, and found it to be almost totally aphyric. It contains a very few rounded (resorbed) sanidine phenocrysts (figure 6) and needle-shaped microlites with high refractive index (pyroxene?). He noted that "The microlites undoubtedly formed during emplacement of the dome, but the resorption of the sanidine phenocrysts must have occurred at depth prior to eruption and probably indicates heating of the source magma chamber with an influx of hotter (basaltic?) magma."
Information Contacts: Gezahegn Yirgu, Dereje Ayalew, Asfawossen Asrat, and Atalay Ayele, Department of Earth Sciences, Addis Ababa University, PO Box: 1176, Addis Ababa, Ethiopia; Anthony Philpotts, University of Connecticut, U-45, Beach Hall, Storres, CT 06269, USA; National Earthquake Information Center (NEIC), US Geological Survey, Geologic Hazards Team Office, Colorado School of Mines, 1711 Illinois St., Golden, CO 80401, USA (URL: https://earthquake.usgs.gov/); The Ethiopian Herald, Addis Ababa, Ethiopia.
This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.
Synonyms |
||||
Boyna | Moina | Boina | ||||
Cones |
||||
Feature Name | Feature Type | Elevation | Latitude | Longitude |
Boina
Dabbaira |
Cone | |||
Craters |
||||
Feature Name | Feature Type | Elevation | Latitude | Longitude |
Da'Ure | Fissure vent | 12° 43' 37" N | 40° 32' 55" E |
|
|
There is data available for 4 confirmed Holocene eruptive periods.
2005 Sep 26 - 2005 Sep 29 Confirmed Eruption VEI: 3 (?)
Episode 1 | Eruption | NE flank (Da'Ure) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2005 Sep 26 - 2005 Sep 29 | Evidence from Observations: Reported | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
List of 9 Events for Episode 1 at NE flank (Da'Ure)
|
3450 BCE ± 1800 years Confirmed Eruption
Episode 1 | Eruption | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
3450 BCE ± 1800 years - Unknown | Evidence from Isotopic: Ar/Ar | ||||||||||||||
List of 1 Events for Episode 1
|
4450 BCE ± 2700 years Confirmed Eruption
Episode 1 | Eruption | North flank | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
4450 BCE ± 2700 years - Unknown | Evidence from Isotopic: Ar/Ar | ||||||||||||||
List of 1 Events for Episode 1 at North flank
|
5850 BCE ± 4300 years Confirmed Eruption
Episode 1 | Eruption | North flank | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
5850 BCE ± 4300 years - Unknown | Evidence from Isotopic: Ar/Ar | ||||||||||||||
List of 1 Events for Episode 1 at North flank
|
There is data available for 3 deformation periods. Expand each entry for additional details.
Reference List: Wright et al. 2006.
Full References:
Wright, T. J., C. Ebinger, J. Biggs, A. Ayele, G. Yirgu, D. Keir, and D. A. Stork, 2006. Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode. Nature, 442, 291-294.
Start Date: 2005 | Stop Date: 2009 | Direction: Variable (uplift / subsidence) | Method: InSAR |
Magnitude: Unknown | Spatial Extent: Unknown | Latitude: Unknown | Longitude: Unknown |
Remarks: Following the large dyke intrusion of September 2005, there were 13 smaller intrusions from June 2006 to Jun 2009. Deformation from these intrusions is modeled by various authors as planar dislocations. Inter-dyking deformation is also modeled. |
Reference List: Hamling et al. 2009; Hamling et al. 2010; Grandin et al. 2010a; Grandin et al. 2010b; Field et al. 2012; Hamling et al. 2014.
Full References:
Field, L., Blundy, J., Brooker, R. A., Wright, T., & Yirgu, G., 2012. Magma storage conditions beneath Dabbahu Volcano (Ethiopia) constrained by petrology, seismicity and satellite geodesy. Bulletin of Volcanology, 74(5), 981-1004.
Grandin, R., A. Socquet, E. Jacques, N. Mazzoni, J.-B. de Chabalier, and G. C. P. King, 2010. Sequence of rifting in Afar, Manda-Hararo rift, Ethiopia, 2005-2009: Time-space evolution and interactions between dikes from interferometric synthetic aperture radar and static stress change modeling,. J. Geophys. Res., 115, B10413. https://doi.org/10.1029/2009JB000815
Hamling, I. J., Wright, T. J., Calais, E., Bennati, L., & Lewi, E., 2010. Stress transfer between thirteen successive dyke intrusions in Ethiopia. Nature Geoscience, 3: 713-717.
Hamling, I. J., Wright, T. J., Calais, E., Lewi, E., Fukahata, Y., 2014. InSAR observations of post-rifting deformation around the Dabbahu rift segment, Afar, Ethiopia. . Geophysical Journal International, 197 (1): 33-49. https://doi.org/10.1093/gji/ggu003
Hamling, I.J., Ayele, A., Bennati, L., Calais, E., Ebinger, C.J., Keir, D., Lewi, E., Wright, T.J. and Yirgu, G.,, 2009. Geodetic observations of the ongoing Dabbahu rifting episode: new dyke intrusions in 2006 and 2007. Geophysical Journal International, 178(2), pp.989-1003.
Start Date: 2004 Apr 16 | Stop Date: 2005 May 06 | Direction: Uplift | Method: InSAR |
Magnitude: 12.000 cm | Spatial Extent: 8.00 km | Latitude: 13.000 | Longitude: 41.000 |
Remarks: Pre-rift uplift at Gabho volcano |
Reference List: Wright et al. 2006.
Full References:
Wright, T. J., C. Ebinger, J. Biggs, A. Ayele, G. Yirgu, D. Keir, and D. A. Stork, 2006. Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode. Nature, 442, 291-294.
There is no Emissions History data available for Dabbahu.
Maps are not currently available due to technical issues.
The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.
There are no samples for Dabbahu in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.
Copernicus Browser | The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions. |
MIROVA | Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity. |
MODVOLC Thermal Alerts | Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales. |
WOVOdat
Single Volcano View Temporal Evolution of Unrest Side by Side Volcanoes |
WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments. |
Volcanic Hazard Maps | The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter. |
IRIS seismic stations/networks | Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of Dabbahu. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice. |
UNAVCO GPS/GNSS stations | Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of Dabbahu. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player. |
DECADE Data | The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO2 to the atmosphere, but installing CO2 monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere. |
Large Eruptions of Dabbahu | Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA). |
EarthChem | EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS). |